Restructure pkg/unittest and pkg/webdriver to follow the pub conventions.

tests/html/queryall_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file
 
-#library('NodeListTest');
-#import('../../pkg/unittest/unittest.dart');
-#import('../../pkg/unittest/html_config.dart');
-#import('dart:html');
+library NodeListTest;
+import '../../pkg/unittest/lib/unittest.dart';
+import '../../pkg/unittest/lib/html_config.dart';
+import 'dart:html';
 
 main() {
   useHtmlConfiguration();
 
   var isElement = predicate((x) => x is Element, 'is an Element');
   var isCanvasElement =
       predicate((x) => x is CanvasElement, 'is a CanvasElement');
   var isDivElement = predicate((x) => x is DivElement, 'is a isDivElement');
 
   var div = new DivElement();
@@ skipping 59 matching lines @@
       expect(list[4], isCanvasElement);
     });
 
   test('immutable', () {
       List<Element> list = div.queryAll('*');
       int len = list.length;
       expect(() { list.add(new DivElement()); }, throwsUnsupportedError);
       expect(list.length, equals(len));
     });
 }